Anomalous Coronary Arteries: Location, Degree of Atherosclerosis and Effect on Survival-A Report From the Coronary Artery Surgery Study

Transcription

1 JACC Vol. 13, No. 1 March : Anomalous Coronary Arteries: Location, Degree of Atherosclerosis and Effect on Survival-A Report From the Coronary Artery Surgery Study ROGER L. CLICK, MD, PHD, FACC, DAVID R. HOLMES, JR, MD, FACC, RONALD E. VLIETSTRA, MB, CHB, FACC, ANDRZEJ S. KOSINSKI, MSc, RICHARD A. KRONMAL, PHD AND THE PARTICIPANTS OF THE CORONARY ARTERY SURGERY STUDY (CASS)* Rochester, Minnesota and Seattle, Washington Limited information is available about clinical presentation, degree of atherosclerosis and effect on overall survival in a large series of patients with coronary artery anomalies. From the National Heart, Lung, and Blood Institute Multicenter Coronary Artery Surgery Study (CASS), detailed coding of coronary angiograms was available in 24,959 patients. Of these patients, 73 (0.3%) had major coronary artery anomalies: 70 had one coronary anomaly and 3 had two coronary anomalies. The most common anomaly involved the circumflex coronary artery (60%). In 69% of these, the circumflex artery arose from a separate ostium in the right coronary sinus, and in 31% it originated as a branch of the right coronary artery. The most common anomalous course was anterior or posterior to the great vessels but not between the great vessels. The major exception to this finding was an anomalous right coronary artery; 7 of 15 such arteries coursed between the great vessels. Anomalous circumflex coronary arteries had a significantly greater degree of stenosis than that in nonanomalous arteries in age- and gender-matched control patients (p = 0.02). Despite this difference, at 7 years there was no significant difference in survival by location or degree of stenosis in the anomalous artery. (J Am Co11 Cardiol 1989;13:531-7) Coronary artery anomalies are found in 0.2% to 1.2% of the population (l-7). Angiographic recognition of the various anomalies may be difficult. Failure to recognize these anomalies may prolong the angiographic procedure or lead to repeat catheterizations (8). An accurate description must be made to ensure that the entire coronary circulation is visualized angiographically so that proper therapy can be selected and planned. If surgical therapy is selected, it is essential to plan the approach to avoid any increased risk of coronary trauma during cardiac surgery (9-13). Furthermore, *A list of CASS investigators and clinical centers appears in J Am Coil Cardiol 1988;12:598. From the Division of Cardiovascular Diseases and Internal Medicine, Mayo Clinic and Mayo Foundation, Rochester, Minnesota and the Coordinating Center, University of Washington, Seattle, Washington. Manuscript received July 25, 1988; revised manuscript received October 6, 1988, accepted October 24, Address for renrints: Roger L. Click, MD. Mayo Clinic, 200 First Street Southwest, Rochester, Minnesota some types of coronary artery anomalies are associated with myocardial ischemia or sudden death, or both (14-23). Previous studies (20,24) have suggested a predilection for accelerated atherosclerosis in some forms of coronary artery anomalies, whereas other studies (1,6,7,18) have not shown an increased incidence of atherosclerosis. Although previous autopsy and angiographic studies (l-7,25,26) have reviewed the various types of coronary anomalies, their proximal and distal course and recognition, little is known about the overall effect of coronary anomalies on clinical presentation and long-term prognosis. The purpose of this paper is to review the Coronary Artery Surgery Study (CASS) data on coronary artery anomalies: incidence, clinical presentation, degree of atherosclerosis and effect on overall survival. Methods Identification of coronary anomalies. The details of the National Heart, Lung, and Blood lnstitute Coronary Artery by the American College of Cardiology 073S-1097/8Y/$3.50

2 532 CLICK ET AL. JACC Vol. 13, No. 3 March 1, 1989:531-7 Table 1. Clinical Characteristics of 73 Patients With Coronary Artery Anomalies and 730 Matched Control Patients Gender Male Female Characteristic Age (yr) < to 545 >45 Predominant symptom Asymptomatic CHF Angina Other Angina (Canadian Heart Class)* None Class I Class II Class III Class IV Unrelated Unknown Duration of angina (weeks) I to4 5 to to 104 I05 to Unknown Evidence of myocardial infarction None Present on ECG Unknown Unresolved Patients With Coronary Anomaly Control Patients No. % No. % I6 22 I I s 70 1 IO 70 IO I3 I IO 6 8 I I5 I II I I3 2 I2 103 I I I I 0.1 *Symptoms within 6 weeks before baseline (entry into the study). CHF = congestive heart failure; ECG = electrocardiogram. Surgery Study have been previously published (27). In that study, detailed coding of coronary angiography was available in 24,959 patients. If a coronary anomaly was identified, it was coded on the reporting form and entered in the central data base. A major coronary anomaly was identified in 73 patients. Each center with coronary anomalies was asked to send the film for review. Each of the 73 patient films was reviewed and coded to determine the affected coronary artery, the location of anomalous origin and the course of the anomalous artery in relation to the aorta and pulmonary artery. The course was defined as either anterior or posterior to the great vessels or between the great vessels (28). For both left and right coronary systems in which right anterior oblique and left anterior oblique views were used, an anterior course was recognized as a cranial anterior loop, a posterior course as a caudal posterior loop and a course between the great vessels as a cranial posterior loop of the Table 2. Anomalous Coronary Artery Origin in 73 Patients Coronary Artery Origin Involved Coronary Artery (No.) LM LAD LCx OM RCA Total From contralateral sinus* Adjacent to ostium 3 31 I Remote from ostium 3 0 I2 I I2 28 From contralateral artery* LAD I I LCX RCA I I I3 I 0 I6 OtherS 2 0 I Total I7 76$ *Origin from the sinus opposite to the normal origin or from an artery in the opposite sinus. tthree patients had two anomalous coronary arteries. All three had an anomalous left circumflex artery and left anterior descending artery, each arising from a separate ostium adjacent to the right coronary artery ostium. SOther origins were left main artery from pulmonary artery, left main artery from posterior cusp, left circumflex artery from distal right coronary artery, right coronary artery from anterior cusp of bicuspid aortic valve and right coronary artery from above the left sinus. Total is 76 because three patients had two anomalous vessels. LAD = left anterior descending artery; LCx = left circumflex artery; LM = left main artery; OM = obtuse marginal artery; RCA = right coronary artery. proximal portion of the anomalous artery. Careful review of multiple angulated views was usually required to determine the exact course of the vessel. The degree of narrowing of the anomalous artery and the rest of the arterial tree was coded. A visual estimate of luminal diameter stenosis was used. Patients with ~30% stenosis were believed to have either normal vessels or minimal disease; stenosis in patients with >30% and ~70% narrowing was classified as moderate and stenosis >70% was graded as severe. Control group. To compare the degree of stenosis in the anomalous artery with that in the same artery in patients with normal anatomy, the patients with one or more anomalous arteries were matched by age, gender, predominant symptoms and degree of stenosis in the nonanomalous arteries with patients who had normal coronary anatomy. For the comparison of stenosis, 10 control subjects from the CASS registry were randomly selected for each patient with an anomaly. In the 10 control subjects, the degree of stenosis in the comparison artery was averaged. Statistical analysis. For comparison between the average stenosis in the control vessel (derived from 10 control subjects) and that in its matched anomalous vessel, the Wilcoxon signed-rank test was used. The Kaplan-Meier product limit estimate was used to describe the survival of various patient subgroups. Statistical tests of the differences among survival curves were based on the log-rank statistic. Because this study is descriptive, all p values should be interpreted with caution. Further, lack of statistical significance may reflect in many instances the low power of the statistical tests due to small sample sizes rather than a true lack of differences.

3 JACC Vol. 13. No. 1 March :531-i CLICK ET AL. 533 i: * I,-- _*,* -._ I._ Figure 1. Left anterior oblique view of anomalous left circumflex artery arising from the right coronary cusp adjacent to the right coronary ostium. *,I, Results Clinical characteristics of patient group (Table 1). Of the 24,959 patients, 73 (0.3%) had anomalous coronary arteries. Fifty-seven were men and 16 were women; the age range was 30 to 73 years. The indication for angiography was chest pain consistent with angina pectoris in 59 patients (80%), evaluation for suspected asymptomatic coronary artery disease in 7 pa- A U l- I Figure 3. Left anterior oblique view of anomalous right coronary artery (arrow) arising from the left coronary sinus. Figure 4. Right anterior oblique (top) and left anterior oblique (bottom) views of anomalous left anterior descending and circumflex arteries arising from the right coronary sinus. The left anterior descending artery courses between, and the circumflex artery courses posterior to, the great vessels. Figure 2. Left anterior oblique view of anomalous left circumflex artery (arrow) arising as a branch from the proximal right coronary artery. tf+++ \ _ -- w U c_ / 7 5 _-

4 534 CLICK ET AL. JACC Vol. 13, No. 3 March 1, Figure 5. Right anterior oblique view of anomalous left anterior descending coronary artery (arrow) arising from the proximal right coronary artery. tients (10%) and part of the evaluation for congestive heart failure in 2 patients (3%). Fifteen patients (21%) had evidence of previous myocardial infarction on the 12 lead electrocardiogram (ECG). Twenty-two patients (30%) were 45 years old or younger at the time of symptoms and angiographic evaluation. Site of anomalous origin of coronary arteries (Table 2). Seventy patients had an anomaly involving a single coronary artery and three had anomalies of two coronary arteries. The most common anomaly, occurring in 44 (60%) of 73 patients, involved the left circumflex artery. In 18 patients, the artery arose adjacent to the right coronary ostium (Fig. 1), whereas in 12 patients, it arose from the right cusp but remote from the right coronary artery ostium. In 13 patients, it arose as a branch of the right coronary artery (Fig. 2). The next most common anomaly involved the right coronary artery (17 Table 3. Proximal Course of 69 Anomalous Coronary Arteries in Relation to the Great Vessels Anomalous Coronary Artery Posterior to GV No. of Arteries Proximal Course Between GV Anterior to GV LM LAD LCX RCA GV = great vessels; other abbreviations as in Table 2. Figure 6. Right anterior oblique (top) and left anterior oblique (bottom) views of anomalous circumflex artery (arrow) arising from the proximal right coronary artery and coursing posterior to the great vessels (that is, a caudal posterior loop). patients), which in most instances arose from the left coronary sinus (Fig. 3). The left main artery was the third most common anomalous coronary artery and was identified in nine patients. In most patients, the anomalous left main artery arose from the contralateral (opposite of normal) sinus (Fig. 4). The least common anomaly (four patients) was of the left anterior descending coronary artery (Fig. 5). Proximal course of anomalous coronary artery (Table 3). In 69 vessels, the proximal course of the anomalous coronary artery could be determined in relation to the great vessels. In the 1.5 patients with a right coronary artery anomaly, the course of the artery was either anterior to the great vessels or between the great vessels to its final epicardial position (Fig. 3). For circumflex artery anomalies, a course posterior to the great vessels was always seen (Fig. 6). For left main and left anterior descending artery anomalies, the course was most commonly anterior to the great vessels and rarely between the great vessels. An example of an anomalous left main coronary artery coursing between the great vessels is seen in Figure 7. Anomalous coronary artery stenosis (Table 4). Thirty anomalous arteries were angiographically normal, 14 had

5 JACC Vol. 13, No. 3 CLICK ET AL. 535 March I, 1989:531-7 Table 5. Comparison of Anomalous Vessel Stenosis in 73 Patients and 730 Control Subjects Anomalous Vessel No. of Vessels* p Valuet Cases Mean Stenosis (%) Control Subjects LM LAD LCX OM RCA I 42.8 *Sum is 76 because three patients had two anomalies; *two-sided p values from Wilcoxon signed-rank test. Abbreviations as in Table 2. control arteries (41% and 29% stenosis, respectively; p = 0.02). Survival of patients with an anomalous coronary artery. Figure 8 shows the 7 year survival curve for persons with the three most frequent anomalous arteries. Although there was a suggestion of poorer survival for patients with an anomalous left circumflex coronary artery at 2 years, at 7 years there was no significant difference. Figure 7. Right anterior oblique (top) and left anterior oblique (bottom) views of anomalous left main coronary artery from the right coronary ostium coursing between the aorta and pulmonary arteries (that is, a cranial posterior loop [arrow]). minor stenosis, 14 (18%) had moderate stenosis and 18 (23%) had severe stenosis. Stenosis in anomalous coronary arteries compared with that in control arteries (Table 5). The degree of stenosis in the anomalous coronary arteries was not significantly different from that in the arteries of matched control patients without anomalies, with the exception of a significantly greater stenosis in anomalous circumflex arteries than in Discussion Coronary artery anomalies are uncommon in adults. However, recognition of the anomaly and correct identification of the course are important for complete anatomic classification at the time of the angiogram and also for safe and complete revascularization in patients who are to have bypass surgery. Prevalence. These results indicate that approximately 3 of every 1,000 adult coronary angiograms show a major coronary artery anomaly. This prevalence is similar to that of previous reports (1,3,4,6,7). The prevalence may be higher if the origin of a coronary artery from an ectopic ostium in the normal sinus is also included (2,.5). Also, the overall incidence in the adult population may be higher because this study only included people with symptoms of coronary artery disease. Table 4. Distribution of Percentage of Stenosis for Anomalous Coronary Vessels in 73 Patients Stenosis (%) LM LAD No. of Arteries LCx OM RCA Total* to to to I 7 71 to to *Sum is 76 because three patients had two anomalous vessels. Abbreviations as in Table 2. Figure 8. Survival by anomalous coronary artery. LCX = left circumflex coronary artery; LMCA = left main coronary artery; RCA = right coronary artery.

6 536 CLICK ET AL. JACC Vol. 13, No. 3 March :531-7 Figure 9. Right anterior oblique view of the origin of the left main coronary artery from the posterior (noncoronary) sinus. Anomaly location. The most frequent coronary anomaly is of the circumflex artery; most commonly, the vessel arises from the right coronary sinus by a separate ostium. Origin of a coronary artery from the noncoronary (posterior) sinus is rare (29). One occurred in this series (Fig. 9); none was described in the series of Engel et al. (2), and Ogden (5) described 1 case of 63 in his review. Course of anomalous vessel. The most common course of the anomalous circumflex coronary artery was posterior to the great vessels. In contrast, for the left main, left anterior descending and right coronary arteries, the most common course was anterograde to the great vessels, except that a large percentage of the right coronary arteries coursed between the great vessels. Stenosis of anomalous artery. Previous studies have suggested either a greater degree of stenosis of the anomalous artery (20,24) or no difference (1,6,7,18). These were isolated observations without comparison with control cases. In this study we are able to clarify this issue by comparing the degree of stenosis in the anomalous artery with matched control cases. We show that stenosis is significantly greater in an anomalous circumflex artery than in a nonanomalous circumflex artery in control subjects matched for age, gender, symptoms and degree of atherosclerosis of nonanomalous coronary arteries. Hutchins et al. (30) suggested that the unusual angle of takeoff and more tortuous course of the proximal portion of the anomalous coronary artery predisposes it to accelerated atherosclerosis. Others (24) have postulated that the junction point of the bound portion of the anomalous artery and the free portion as it wraps around the aorta is an area susceptible to lipid accumulation. The posterior course of the circumflex artery would be consistent with these theories, whereas the anterior or interarterial course does not show the same degree of tortuosity or angulation. It has been assumed that the stenosis in anomalous coronary arteries is due to atherosclerosis; however, the vessel may be hypoplastic or a segment may be stretched. Survival. In this study, because of the large number of patients and long-term follow-up, survival could be assessed. Despite an increase in stenosis of the anomalous circumflex artery, survival was not adversely affected. Although at 3 years there was a trend for poorer survival with an anomalous circumflex artery, by 7 years there was no difference. Conclusions. Of the 24,959 patients in this series, 0.3% had a major coronary anomaly, the most common being the left circumflex artery arising from the right coronary sinus. The most common course of the proximal portion of the anomalous circumflex artery was posterior to the great vessels. The anomalous circumflex artery demonstrated greater stenosis than did control coronary arteries. References 1. Alexander RW, Griffith GC. Anomalies of the coronary arteries and their clinical significance. Circulation 1956:14X Engel HJ, Torris C, Page HL Jr. Major variations in anatomical origin of the coronary arteries: angiographic observations in 4,250 patients without associated congenital heart disease. Cathet Cardiovasc Diagn 1975;1: Baltaxe HA, Wixson D. The incidence of congenital anomalies of the coronary arteries in the adult population. Radiology 1977;122: Kimbiris D, Iskandrian AS, Segal BL, Bemis CE. Anomalous aortic origin of coronary arteries. Circulation 1978;58: Ogden JA. Congenital anomalies of the coronary arteries. Am J Cardiol 1970;25:474-9.

7 JACC Vol. 13. No.? March I, 1989:531-7 CLICK ET AL Page HL Jr, Engel HJ, Campbell WB, Thomas CS Jr. Anomalous origin of the left circumflex coronary artery: recognition, angiographic demon- stration and clinical significance. Circulation 1974:50: Chaitman BR, Lesptrance J, Saltiel J, Bourassa MG. Clinical, angiographic, and hemodynamic findings in patients with anomalous origin of the coronary arteries. Circulation 1976;53: Donaldson RM, Raphael MJ. Missing coronary artery: review of technical problems in coronary arteriography resulting from anatomical variants. Br Heart J 1982:47: Neufeld HN. Bheden LC. Coronary artery disease in children. Prog Cardiol 1975;4:11Y-4Y. IO. Moodie DS. Gill C. Loop FD, Sheldon WC. Anomalous left main coronary artery originating from the right sinus of Valsalva: pathophysiology, angiographic definition, and surgical approaches. J Thorac Cardiovasc Surg 198O:SO: II. Mustafa I, Gula G. Radley-Smith R, Durrer S, Yacoub M. Anomalous origin of the left coronary artery from the anterior aortic sinus: a potential cause of sudden death: anatomic characterization and surgical treatment. J Thorac Cardiocasc Surg ly81;82: Hallman GL, Cooley DA, Singer DB. Congenital anomalies of the coronary arteries: anatomy, pathology. and surgical treatment. Surgery 1966:59: Roberts WC, Morrow AG. Compression of anomalous left circumflex coronary arteries by prosthetic valve fixation rings. J Thorac Cardiovasc Surg 1969:57:83M. 14. Jokl E, hkclelbdn JT. Williams WC, Gauze FJ. Bartholomew RD. Congenital anomaly of left coronary artery in young athletes. Cardiologia 1966;49: Cohen LS, Shaw LD. Fatal myocardial infarction in an I I year old boy associated with a unique coronary artery anomaly. Am J Cardiol 1967:19: Liberthson RR, Dinsmore RE. Bharati S, et al. Aberrant coronary artery origin from the aorta: diagnosis and clinical significance. Circulation ly74:50: IY. Cheitlin MD, De Castro CM. McAllister HA. Sudden death as a complication of anomalous left coronary origin from the anterior sinus of Valsalva: a not-so-minor congenital anomaly. Circulation 1974:50:78& Silverman KJ. Bulkley BH. Hutchins GM. Anomalous left circumflex coronary artery: normal variant of uncertain clinical and pathologic significance. Am J Cardiol 1978:41: I31 14.?I. Liberthson RR. Dinsmore RE, Fallon JT. Aberrant coronary artery origin from the aorta: report of 18 patients, review of literature and delineation cf natural history and management. Circulation 1979;59: Murphy DA. Rov DL. Sohal M. Chandler BM. Anomalous origin of left main coronary artery from anterior sinus of Valsalva with myocardial infarction. J Thorac Cardiovasc Surg 1978:75: Levin DC. Fellows KE, Abrams HL. Hemodynamically significant primary anomalies of the coronary arteries: angiographic aspects. Circulation 1978;58: Liu LB. Richardson T, Taylor CB. Atherosclerotic occlusions in anomalous left circumflex coronary-arteries: a report of 2 unusual cases and a review of pertinent literature. Par Arter ly75;2: Blake HA. Manion WC, Mattingly TW. Baroldi G. Coronary artery anomalies. Circulation 1964;30: Vlodaver Z. Neufeld HN, Edwards JE. Pathology of coronary disease. Semin Roentgen :7: ( ASS Principal Investigators and Their Associates. Coronary Artery Surgery Study (CASS): a randomized trial of coronary artery bypass surgery survival data. Circulation 1983:68:93Y Ibhikawa T. Brandt PWT. Anomalous origin of the left mam coronary artery from the right anterior aortic sinus: angiographic definition of anomalous course. Am J Cardiol 1985:55: Benson PA, Lack AR. Anomalous aortic origin of left coronary artery. IY. Smith GT. The anatomy of the coronary circulation. Am J Cardiol 1962:Y: Arch Pathol 1968:86: Benson PA. Anomalous aortic origin of coronary artery with sudden death: case report and review. Am Heart J 1970;79: Hutchins GM. Miner MM, Boitnott JK. Vessel caliber and branch-angle of human coronary artery branch-points. Circ Res 1976:38:5726.